GeekTechStuff

Argo CD has options to deploy apps via a web GUI in a click ops fashion, but the same can be achieved using some YAML.

Argo CD Application YAML

The Argo CD application can be defined and applied via a YAML file, allowing for the configuration of apps to be saved in version control.

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: geek.app
  namespace: argocd
spec:
  project: default
  destination:
    namespace: default
    name: in-cluster
  source:
    helm:
      valueFiles:
        - values.yaml
    repoURL: https://github.com/geektechdude/helm-basic-chart
    path: .
  syncPolicy:
    automated:
      enabled: true

Saving this YAML as geekapp.yaml, it can then be applied via a kubectl apply:

 kubectl apply -f geekapp.yaml

The Argo CD app will then show in the Argo CD web GUI as normal.

Breaking Down The YAML

apiVersion: argoproj.io/v1alpha1
kind: Application

This is telling Kubernetes that an Application (kind:Application) is being created using the specifications of argoproj.io/v1alpha1.

metadata:
  name: geek.app
  namespace: argocd

This is the name of the application (geek.app) in Argo CD, and deploys the resource for the Argo CD application into the namespace Argo CD is running in (for me it’s a namespace called argocd).

spec:
  project: default
  destination:
    namespace: default
    name: in-cluster
  source:
    helm:
      valueFiles:
        - values.yaml
    repoURL: https://github.com/geektechdude/helm-basic-chart
    path: .
  syncPolicy:
    automated:
      enabled: true

The specifications of the application and where the applications resources (pods, load balancer) should be deployed to. I’m deploying the resources to the default namespace of my Kubernetes cluster (namespace: default) and that is the cluster I have Argo CD deployed on (name: in-cluster).

My repository contains a value file called “values.yaml” that contains values I want to use with the deployment, so the “source > helm > valueFiles” tells Argo CD about the file.

repoURL is the location of the repository containing the Helm chart with the deployment resource details within, and the path (“.”) is saying where in the repository the chart it.

syncPolicy > automated is true which is telling Argo CD to automatically sync with the repository and make changes when detected in the repository.